Bastien Montagne
85c9aefe0f
This is in fact very hairy situation here... Objects are only refcounted by scenes, any other usage is 'free', which means once all object instanciations are gone Blender considers it can delete it. There is a trap here though: indirect usages. Typically, we should never modify linked data (because it is essencially useless, changes would be ignored and ost on next reload or even undo/redo). This means indirect usages are not affected by default 'safe' remapping/unlinking. For unlinking preceeding deletion however, this is not acceptable - we are likely to end with a zero-user ID (aka deletable one) which is still actually used by other linked data. Solution choosen here is double: I) From 'user-space' (i.e. outliner, operators...), we check for cases where deleting datablocks should not be allowed (indirect data or indirectly used data), and abort (with report) if needed. II) From 'lower' level (BKE_library_remap and RNA), we also unlink from linked data, which makes actual deletion possible and safe. Note that with previous behavior (2.77 one), linked object would be deleted, including from linked data - but then, once file is saved and reloaded, indirect usage would link back the deleted object, without any instanciation in scene, which made it somehow virtual and unreachable... With new behavior, this is no more possible, but on the other hand it means that in situations of dependency cycles (two linked objects using each other), linked objects become impossible to delete (from user space). Not sure what's best here, behavior with those corner cases of library linking is very poorly defined... :(
82 lines
2.5 KiB
C++
82 lines
2.5 KiB
C++
/*
|
|
* ***** BEGIN GPL LICENSE BLOCK *****
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version 2
|
|
* of the License, or (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software Foundation,
|
|
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
*
|
|
* The Original Code is Copyright (C) 2014 by Blender Foundation.
|
|
* All rights reserved.
|
|
*
|
|
* Contributor(s): Sergey SHarybin.
|
|
*
|
|
* ***** END GPL LICENSE BLOCK *****
|
|
*/
|
|
#ifndef __BKE_LIBRARY_QUERY_H__
|
|
#define __BKE_LIBRARY_QUERY_H__
|
|
|
|
/** \file BKE_library_query.h
|
|
* \ingroup bke
|
|
* \since March 2014
|
|
* \author sergey
|
|
*/
|
|
|
|
struct ID;
|
|
struct Main;
|
|
|
|
/* Tips for the callback for cases it's gonna to modify the pointer. */
|
|
enum {
|
|
IDWALK_NOP = 0,
|
|
IDWALK_NEVER_NULL = (1 << 0),
|
|
IDWALK_NEVER_SELF = (1 << 1),
|
|
|
|
/**
|
|
* Adjusts #ID.us reference-count.
|
|
* \note keep in sync with 'newlibadr_us' use in readfile.c
|
|
*/
|
|
IDWALK_USER = (1 << 8),
|
|
/**
|
|
* Ensure #ID.us is at least 1 on use.
|
|
*/
|
|
IDWALK_USER_ONE = (1 << 9),
|
|
};
|
|
|
|
enum {
|
|
IDWALK_RET_NOP = 0,
|
|
IDWALK_RET_STOP_ITER = 1 << 0, /* Completly stop iteration. */
|
|
IDWALK_RET_STOP_RECURSION = 1 << 1, /* Stop recursion, that is, do not loop over ID used by current one. */
|
|
};
|
|
|
|
/**
|
|
* Call a callback for each ID link which the given ID uses.
|
|
*
|
|
* \return a set of flags to control further iteration (0 to keep going).
|
|
*/
|
|
typedef int (*LibraryIDLinkCallback) (void *user_data, struct ID *id_self, struct ID **id_pointer, int cd_flag);
|
|
|
|
/* Flags for the foreach function itself. */
|
|
enum {
|
|
IDWALK_READONLY = (1 << 0),
|
|
IDWALK_RECURSE = (1 << 1), /* Also implies IDWALK_READONLY. */
|
|
};
|
|
|
|
/* Loop over all of the ID's this datablock links to. */
|
|
void BKE_library_foreach_ID_link(struct ID *id, LibraryIDLinkCallback callback, void *user_data, int flag);
|
|
void BKE_library_update_ID_link_user(struct ID *id_dst, struct ID *id_src, const int cd_flag);
|
|
|
|
int BKE_library_ID_use_ID(struct ID *id_user, struct ID *id_used);
|
|
|
|
bool BKE_library_ID_is_indirectly_used(struct Main *bmain, void *idv);
|
|
|
|
#endif /* __BKE_LIBRARY_QUERY_H__ */
|